I've been doing this successfully in my project, but have just discovered that on some mobiles onSelectionChanged() IS called, and in others it is not being called. Both > Android 4.0 ....
–
Andrew MackenzieDec 13 '12 at 17:00

For this application it would be better to have your toast length SHORT
–
kyle kJan 1 '14 at 6:35

I have been debugging a related problem between an HTC with 4.0.6 and a Samsung with 4.1.6

Summary of my findings:

4.1.6
onSelectionChanged() gets called on TEXT EDITS

4.0.0
onSelectionChanged() gets called on cursor changes (clicks, moves etc) but NOT on Text Edits.
You will have to detect the cursor change using a TextWatcher, for example in the afterTextChanged() method.

Oh goodness, thanks so much for this idea. There's absolutely no reason why this feature shouldn't be in the SDK. I have an quick subclass that implements this idea but adding on the additional feature of listeners for when the selection changes. Hope it's useful